Pneumatic tire.



F. COLBY.

PNEUMATIC TIRE.

APPLICATION FILED MAY 2. I9Ia.

Patented Aug. 27, 1918.

O NI

ATTORNEYS @einen sans couler, or 'roxane Panis, New Yoan.

PNEUMTIC TIRE.

imams.

Specification of Letters Patent.

Patented Aug. 27, 1918.

Application led May 2, 1918. Serial No. 765,024.

To all 'whom-t may concern:

Beit known that I, FRED COLBY, a citizen of the United States, and a resident of Tuxedo Park, Iin the county of Orange and State of New York, have invented a new and Improved 'Pneumatic Tire, of which the f ollowing is a full, clear, and exact description.

This invention relates to resilient pneumatic tires for bicycles, motorcycles, automobiles or other vehicles, and has particular reference to a protecting armor for a pneumatic tire having the usual resilient qualities. v

Among the objects of the invention, stated more definitely, is to provide a pneumatic tire of any well known or a proved construction with respect to attaching or clenching means, such tire possessing the highest possible degree of resiliency and being provided with a removable or replaceable auxiliary tread member which receives the major portion of the wear, whereby when the tread becomes Worn or damaged a new one may be substituted in its place at a comparatively slight cost and with the minimum delay as to time.

' A further object of the invention is to provide a pneumatic tire of such a construction and nature as to be adapted for use in connection with a detachable auxiliary,

tread, such tire, however, beingcomplete in itself and usable in the usual way either with or without the auxiliary tread.

The inventiomnfurthermore, includes certain details of construction whereby the ailxiliary tread is maintained in position by 1mproved and simple means. Y

The foregoing and other` objects of the invention will be hereinafter more fully `described and claimed and illustrated in the drawings forming-a part of this specification in which like characters of reference indicate corresponding parts in all the views, and in which- Figure 1 is a sectional view in perspective of a neumatic tire made in accordance with this invention;

iexible materials, and the relative sizes and proportions of the structural features may be varied to a considerable extent Without departing from the spirit of the invention hereinafter more fully set forth and speciically claimed. v

As shown especially in Fig. 1, the main tire 10 is of a unitary or one piece construction and shown as provided with a well known or conventional form of clencher flanges 1.1. For the sake of liexibility the side portions 12 are comparatively thin, and at 13 is shown the tread portion of this part of the device. The tread 13 is preferably heavier and thicker than the side portions 12 and is adapted for practical use as a tire in the form shown in Fig. 1, especially for emergency purposes. The tread member 13 down'the side portions 12 as may be desired,

and in the form illustrated that portion terminates on either side in a similar groove 15.

At 16 is shown the auxiliary tread member, the same being concavo-convex in section and constituting an endless band or annulus snugly fitted to the periphery of the.

tread member 13 of the main tire. The member 16 is made of rubber or other elastic material and has a reinforcing concentric band 18 of pliable non-yielding material, such as the ordinary canvas fabric of the .typecommonly employed in the manufacture of tires of this class, but constructed of suicient thickness and firmness to give to and maintain in the tread member the definite body form substantially as shown, and is made to extend substantially to the full width of the tread member 13 and is made preferably of uniform thickness in a contin uous circumferential band of the width in dicated. In practice I preferably wind the strips composing the webbing longitudinally of said tread member, whereby itA is pracpurpose of thus olding the shape of the member. But on the other hand, when the webbing has been built up to sufficient depth' to give thetrequired form and rigidity to the Aticable to have a hinner webbing serve the' member, and proper care is exercised to retain the desired form thereof, a bias winding of the usual type may be employed. Hence as the member 16 conforms tothe curvature of the tread 13, the band of webbing 18 extends laterally along the rounded sides 12 and it will accordingly be seen is of relatively reduced diameter and circumferential length at the respective sldes thereof, 1n comparison with the peripheral dimensions of the tread 13 of an inflated t1re. The lnner surface, therefore, of the auxiliary tread 16 isshaped complemental to the exterior s urface of the tread 13; that is to say, being provided with concavities 14 corresponding in form, size and number to the convexitles 14 above described. The webbing 18 also laterally rounded, as pointed out, parallels the inner surface of the member 16 immediately over the concavities 14 down to the edges 17 of the tread member. Thus, the annular webbing 18, when the tire is properly inflated, is adapted to hold the projections 14 into the corresponding retaining cavities 14 at the respective sides as well as upon the other portions of the periphery 18 of the main tire; and furthermore, the edges of the web 18 likewise act in the capacity of retaining the edges 17 into the grooves 15, and in return using the said grooves as a fulcrum, exert an increased locking pressure upon the cavities 14 of the member 16 in their respective positions over the corresponding raised portions 14.

The edges 17 of this tread member are adapted to extend into and remainseated in the grooves 15 aforesaid for the purpose above pointed out, and also that of excluding water, sand or other extraneous matter from working between the two portions of the device when in `use. When the main tire is deflated, the auxiliary tread may easily be slipped in place, and when the tire is inflated in the usual way, the auxiliary tread will be rigidly secured in place and prevented by the convexities 14 from displacement eitherA laterally or circumferentially. y In other words, so far as the possibility of displacement of the auxiliary tread is concerned, the anges forming the grooves on the sides 15 of the main tire may be omitted, although in practice I prefer to employ such anges primarily for the purpose of preventing the entrance of sand or the like between the'contacting surfaces of the two parts.

With the tire arranged as shown in Fig. 3, it is exceedingly strong and reliable because ofthe extra'thickness of material at the particular place where the maximum strain and wear are brought. The main wear and tear being brought upon the auxiliary member,

fact that a large majority of accidents to tires in practical use are due to blowouts, cuts or punctures occurring along the actual treads, I provide a means whereby a single tire may be used for an indenite length of time, much longer than the usual life of a tire providing, of course, suflicient auxiliary treads are used in connection therewith for the purpose. I wish it understood, however, that the tire 10 may be regarded as a complete tire and usable as such without the auxiliary tread in the event of the disability of the auxiliary tread. In other words, if it should be that the tire '10 should lose its aux- 4-iliary tread while on the road, and another one is not available to take the place of the lost tread, the tire 10 under ordmary conditions would carry the vehicle to the end of its journey with a reasonable degree of safety.

I am aware that it has been proposed heretofore to employ auxiliary and renewable treads f or pneumatic tires, but I believe it is new 1n my invention to provide a construction of the character set forth in which there is employed a complete tire usable as such, but having provislon for the attachment of an auxiliary tread to provide for the usual wear and strain.

Having thus described my invention, I

claim as new and desire to secure by Letters versely rounded periphery with spherical protuberances -thereon and terminating in lateral annular grooves, a separable tread member having edges adapted to said grooves and concavities corresponding with said spherical protuberances; and retaining means comprising la relatively non-yielding circumferentially disposed band within said tread member adjacent said concavities and extending into the edges of said member.

2. In a pneumatic tire having a transversely rounded tread portion with annular grooves at the sides and a series of protuberances upon the rounded portion upon the periphery of said tread portion and at the sides thereof, a separable tread member having concavities for said protuberances and edges adapted to said grooves; and retaining means comprising a non-yielding liexible band extending from one edge to the other immediately adjacent said concavities, said protuberances and concavities coacting to lock the edges of said tread member in said grooves.

3. In a pneumatic tire having a transversely rounded tread portion with annular grooves at the sides and spherical protuberances upon the surface thereof, a separable tread member of resilient material having concavities corresponding to said protuberance and edges adapted to saidl grooves; and retaining means comprising a band of iexible, non-yielding material disposed Within name to this specification in the presence of said menber inmediately river slaid clncavitwo subscribing Witnesses. ties an exten in into t e e es t ereo said band havinggthe circumfeential por- FRED COLBY 5- tions Within the edges of relatively reduced Witnesses:

diameters. GEO. L. BEELER,

In testimony whereof I have signed my PHILIP D. ROLLHAUS. 

